1871.] SL 
5 
Elachista Megerlella. Lithocolletis ulicicolella. 
re Gregsoni. is caledoniella. 
5 subnigrella. Cemiostoma lathyrifoliella. 
Lithocolletis viminiella. Nepticula poterii. 
35 nigrescentella. m atricollis. 
= irradiella. Oxyptilus teucrii. 
45 triguttella. 
It is not supposed that these are all peculiar to our islands. 
Melissobiaptes cephalonica is, of course, only an accidental importation 
and not British at all; but it is important to have as complete a list as 
possible, and then it becomes easy to register any additions, or, more 
_ probably, any elisions, which time renders necessary. Yet even now it 
is not going too far to say that our isles present no focus or centre for 
any peculiar group of Lepidoptera. 
6 Naturalized species. 
In a country like England, where civilization has been the growth 
of centuries, and from which the mainland of Europe is so easily 
reached, it is now utterly impossible to estimate with truth what the 
effects of naturalization may have been: when we find our social insects 
as they may be termed, so rapidly acclimatized in America with a dis- 
tance of eleven days between us, how much the more must the same 
be expected with a distance of not nearly as many hours from the 
continent! Pieris rape, Sesia tipuliformis, and Semasia pomonella have 
now a firm home across the Atlantic, and tipuliformis has even found a 
lodging in the Antipodes. In our own days, Dreissena polymorpha 
amongst Molluses, Cynips Kollari amongst insects, and Anacharis alsin- 
astrum amongst plants, have so naturalized themselves in our island, 
that it would be utterly impossible to eradicate them. Of these examples, 
Cynips Kollari is to me of special interest: although noticed by me in 
Devon, certainly for forty years at the least (since we used its galls for 
marbles when I was quite a child), yet it did not reach Birmingham 
until 1860, when it was first noticed by me in the town, a fact not to be 
wondered at, considering how often its galls were brought from the 
south by tourists; it was not, however, until the autumn of 1866 that 
it was first seen by me invading Birmingham, along the hedges on the 
Worcestershire side ; the two streams have since met, and C. Kollari is 
to be found both intown and country. It is not impossible that Pieris 
rape and P. brassice may have come in with the pot-herbs of the old 
Romans, for we know not what human agency may have done 1n the lapse 
of centuries ; yet, as naturalization affects almost entirely such insects as 
haunt the neighbourhood of man, it scarcely touches the general con- 
clusions at which we have arrived. 
